Inguinal hernia repair prosthesis

ABSTRACT

An implantable prosthesis intended, primarily for the repair of muscle wall defects such as occur in inguinal hernias is fabricated from a surgically compatible mesh material having a prismatic external mesh wall ( 1 ). The prismatic shape includes three lobes ( 2 ), providing a generally triangular cross-sectional shape. The shape is maintained by internal reinforcing ribs ( 3 ), which here extend the length of the prism. The ribs are formed through the connection of three individual mesh strips ( 4 ), with each rib comprising two strip parts forming a lamination extending the length of the prism. With this construction closure of elongate legions is readily achieved and a wide range of elongate shapes and dimensions of hernias can be treated.

This application is the US national phase of international applicationPCT/GB2004/000078, filed 12 Jan. 2004, which designated the U.S. andclaims priority of GB 0300784.6, filed 14 Jan. 2003, the entire contentsof each of which are hereby incorporated by reference.

This invention relates to an implantable prosthesis intended, primarilyfor the repair of muscle wall defects such as occur in inguinal hernias.

Prosthetic mesh materials are known for the repair and reinforcement ofmuscle walls. In one technique the mesh is formed into a conical shapeforming a plug which is inserted in the hernia defect, often withplacement of an additional sheet of flat mesh, to close the defect. Inanother form, shown in EP 0614650, there is disclosed a conical plug ofa mesh material configured with pleats and having inserted petal-likeparts. This is stated to have an improved closure performance. The knowndevices are all useful for, and concerned with, closure of generallylocalised, or circular plan defects and it has been found thatdifficulties may occur when the defect opening has a more longitudinaldimension, as is seen with a direct inguinal hernia defect inparticular. Here, one or more conical or circular plan plugs ispotentially unsatisfactory.

It is one object of this invention to provide an implantable prosthesiswhich performs to an enhanced degree for inguinal hernias having a morerectangular or elongate opening and in particular, for direct hernias.

According to this invention there is provided an implantable prosthesisfor the repair of muscle wall defects such as occur in inguinal hernias,the prosthesis comprising a flexible plug of a surgically compatiblemesh material, characterised in that the plug has an elongate form withone portion at least of the surface of the plug forming a projectinglongitudinal ridge or bulge.

In a advantageous shape a portion of the surface of the plug maycomprise a projecting lobe formed by, or on, the surface. In a preferredarrangement the plug has a prismatic shape with a generally triangularcross-section.

In a preferred prosthesis according to this invention the cross-sectionof the plug has a three lobed profile. The apices of the lobes may bejoined by linear sides, providing a generally triangular cross-section.More than three lobes, or ridges, may be provided.

With a construction of this kind it has been found, surprisingly, thatclosure of elongate legions is readily achieved and the plug serves forclosure of a wide range of elongate shapes and dimensions of hernias.

The elongate mesh material forming the plug preferably has internallongitudinal support webs to support the profile of the mesh. These websmay be an integral part of the mesh configured by folding or formed byseparate parts bonded to the inner surface of the outer profile. Inanother construction three, or more, elongate sub-units may be connectedto form the complete prosthesis. Such sub-units may themselves be of atriangular profile.

The wall of the mesh may be pleated circumferentially, or longitudinallyto provide a degree of flexibility and compressibility, to facilitateplacement into the defect comprising the hernia. For each requirementthe mesh plug can be cut to an appropriate required dimension from astock length piece. This is in contrast to known prostheses which are ofpre-determined dimensions whose size, for placement, must be judgedcarefully by the operating surgeon.

In an alternative construction the plug comprises a plurality ofindividual units connected in a longitudinal side-by-side relationship.Such units may individually have a prismatic profile.

This invention also embraces a construction wherein the plug has an openside being in the form of a triangular profiled trough, the shape thenbeing maintained by internal support formed by mesh material.

Hitherto, a size mis-match issue has proved difficult to resolve withknown plugs and the use of two or more plugs is expensive and can leadto unnecessary manipulation during the closure process, Herniarecurrence might occur. The present invention avoids such a basicproblem and may be used with elongate and rectangular openings such asfound, in particular, with direct inguinal hernia defects to which knownplugs may provide an unsatisfactory repair.

The mesh material may be polypropylene and any jointing required may beachieved, for example, by heat sealing. Materials and techniques for themanufacture of surgical mesh materials of the kind useful in carryingout this invention are well known in the art and are not thereforefurther described in any more detail.

Embodiments according to this invention are described in more detailwith reference to examples illustrated in the drawings. In the drawings:

FIG. 1 shows a first embodiment of a prosthesis with internal websupport and according to this invention,

FIG. 2 shows a second embodiment of prosthesis made from sub-units,

FIG. 3 shows a third embodiment of prosthesis with internal support, and

FIG. 4 shows a fourth embodiment with a further internal support.

Referring to FIG. 1, an implantable prosthesis intended, primarily forthe repair of muscle wall defects such as occur in inguinal hernias isfabricated from a surgically compatible mesh material having a prismaticexternal mesh wall 1. The prismatic shape includes three lobes 2,providing a generally triangular cross-sectional shape. The shape ismaintained by internal reinforcing ribs 3, which here extend the lengthof the prism, although discrete spaced ribs may be provided for certainapplications. The ribs are formed through the connection of threeindividual mesh strips 4, with each rib comprising two strip partsforming a lamination extending the length of the prism.

FIG. 2 shows a second embodiment according to this invention wherein theprism 20 is formed from three sub-units 21 (shown separated here), witheach sub-unit 21 having a triangular shape in cross-section. Thesub-units 21 are joined by suitable and known techniques to form thecomplete prosthesis.

The embodiment shown in FIG. 3, is a variation of that shown in FIG. 1where the internal supporting ribs comprise two back-to-back L-shapedsupports, with the base limbs 31 lying on the lower internal side of theprism and the vertical limbs 30 extending together to the upper lobe 32.Lateral reinforcement 33 may be provided.

FIG. 4 shows a construction similar to FIG. 3 but here the base limbs 31of the two L-shaped supports 30 extend around the internal profile ofthe opposed lobes 33 and 34.

In all the embodiments, and according to a feature of this invention,the mesh material may be ridged, pleated, crumpled, or folded to stiffenor pad out the prosthesis this being with particular reference to theinternal supports or webs.

In each case, the plug device is intended, primarily for placement into(direct) inguinal hernia defects. From stock lengths, the device can becut exactly to the correct size. The plug can be sutured into place, ortissues sutured over to hold it in place. The plug may be used with asecond, flat, overlying piece of mesh to thus form a tension-freerepair.

In contrast to known conical plug devices which, when used together,have gaps between the apices allowing gut penetration, the presentinvention provides a single elongate plug which can be cut to size thusproviding better closure and more resistance to penetration by the gut.

The invention claimed is:
 1. An implantable prosthesis for the repair ofmuscle wall defects, the prosthesis comprising a flexible plug of asurgically compatible mesh material, the plug having an elongate formand comprising an external mesh material wall; wherein: the externalmesh material wall has three outwardly projecting longitudinal ridges orbulges which provide the plug overall with a closed generally triangularcross-sectional shape; and the plug further comprises an internalsupport extending into contact with respective interiors of at leastoutermost portions of the outwardly projecting longitudinal ridges orbulges, the internal support extending linearly along the interior of atleast a substantial portion of the external mesh material wall betweenat least two apices of the generally triangular cross-sectional shapeand being sufficiently rigid to maintain the size and shape of theexternal mesh material wall.
 2. An implantable prosthesis in accordancewith claim 1, wherein the plug has a prismatic shape.
 3. An implantableprosthesis in accordance with claim 1, wherein the plug is cut to anappropriate required dimension from a stock length piece.
 4. Animplantable prosthesis in accordance with claim 3, wherein the meshmaterial includes at least one joint, said joint being achieved by heatsealing.
 5. An implantable prosthesis in accordance with claim 1,wherein the mesh material comprises polypropylene.
 6. An implantableprosthesis in accordance with claim 1, wherein the internal supportcomprises longitudinal webs internally of the external mesh materialwall.
 7. An implantable prosthesis in accordance with claim 6, whereinthe webs are formed by separate parts bonded to an inner surface of theexternal mesh material wall.
 8. An implantable prosthesis in accordancewith claim 1, wherein the external mesh material wall comprises meansfor stiffening the prosthesis.
 9. An implantable prosthesis for therepair of muscle wall defects, the prosthesis comprising a flexible plugof a surgically compatible mesh material, the plug having an elongateform and comprising an external mesh material wall; wherein: theexternal mesh material wall has three outwardly projecting longitudinalridges or bulges which provide the plug overall with a closed generallytriangular cross-sectional shape; and the plug further comprises aninternal support extending into contact with respective interiors of atleast outermost portions of the outwardly projecting longitudinal ridgesor bulges, the internal support being sufficiently rigid to maintain thesize and shape of the external mesh material wall, wherein the internalsupport comprises a pair of L-shaped supports positioned back to backand extending into the outwardly projecting longitudinal ridges orbulges.